Polyurethane Foams as Synthetic Soils for Horticulture: food quality and end-of-life recycling

Background
A broad group of University of Sheffield researchers have developed low consumption hydroponics that to combine physical and digital systems in a manner suited to the environment and available resources. A key component of these systems is a soil-free medium for plant growth that is based on polyurethane foam. PU foam is ideally suited to such applications having tunable properties through the polymerisation reaction chemistry. Having come to an understand the physical structure and properties required for plant growth it is now timely to understand the sustainability comparators for PU foam (compared to conventional media) and optimise the structure for food quality and end-of-life recycling and reuse.

Research Objectives
To characterise the structure and performance of a range PU foam forming systems for plant production. To understand the process of foam-to-plant-to-crop in terms of food safety. Use modern, mass-spectrometry metabolomics methods to characterise the microbiome that develops on the foam and any degradation and leaching from the substrate into the crop. To develop new PU polymers suitable for end-of-life processing via biodigestion, follow the degradation and ultimate fate of the PU. Investigate the use of catalyst free formulations with polyester polyols. Follow degradation in the biodigester with particular interest in the aromatic amines resulting from the diisocyanate residues.

Collaborations
Dow Chemicals will contribute the CASE Award part of this project in conjunction with the Institute for Sustainable Food, one of the University of Sheffield's four flagship research institutes: https://www.sheffield.ac.uk/sustainable-food/. The Institute conducts basic, translational and transformative research, taking the latest scientific knowledge and applying it in real-world settings, to ensure that the production and consumption of the world's food is sustainable and resilient